Method of synthesis and novel compounds for pharmaceutical uses

ABSTRACT

The present invention is concerned with a method for treating hemoglobin or blood in vivo or in vitro to modify the affinity of hemoglobin for oxygen, said method comprising causing an effective amount of a substituted arylureidophenoxymethyl propionic acid to come in contact with hemoglobin.

This is a divisional of application Ser. No. 07/821,409, filed Jan. 15,1992, now U.S. Pat. No. 5,292,935, which is a divisional of applicationSer. No. 07/477,048, filed Feb. 7, 1990, now U.S. Pat. No. 5,093,367;which is a divisional of application Ser. No. 07/207,098, filed Jun. 15,1988 which is U.S. Pat. No. 4,921,997issued May 1, 1990.

BACKGROUND OF THE INVENTION

The present invention is concerned with a process for the synthesis ofnovel substituted arylureidophenoxymethylpropionic acids and ananalogous benzamido series of compounds which have exceptional activityin the, dissociation of oxygen from hemoglobin. In addition the novelprocess may be utilized to prepare compounds which are known.

Accordingly, it is a primary object of this invention to provide animproved method for the synthesis of arylureidophenoxymethylpropionicacids.

It is also an object of this invention to provide novelarylureidophenoxymethyl propionic acids.

These and other objects will become apparent from the presentspecification.

SUMMARY OF THE INVENTION

The present invention is concerned with a novel process for thepreparation of compounds of the formula: ##STR1## wherein R₁, R₂, R₃, R₄and R₁₁ may be the same or different and are independently selected fromthe group consisting of hydrogen, halogen, straight or branched chainalkyl of from 1-6 carbon atoms, aryl, cycloalkyl of 3 to 7 carbon atoms;and alkoxy of 1 to 6 carbon atoms; R₅ and R₆ may be the same ordifferent and are selected from the group consisting of hydrogen,halogen, straight or branched chain alkyl groups of from 1 to 6 carbonatoms; aralkyl groups wherein the alkyl portion has from 1 to 6 carbonatoms, cycloalkyl of from 3 to 7 carbon atoms and aryl; R₇ is hydrogenor a straight or branched chain alkyl group of 1 to 6 carbon atoms andthe pharmaceutically acceptable salts thereof such as the sodium,potassium, ammonium etc.

The invention is also concerned with novel compounds of the formula:##STR2## wherein R₄, R₅, R₆ and R₇ are the same as hereinabovedescribed; R₈ is halogen; R₉ is halogen or hydrogen; R₁₀ is halogen orhydrogen; R₁₂ is hydrogen or halogen with the proviso that R₉ may onlybe hydrogen when R₈ and R₁₂ are halogen and the pharmaceuticallyacceptable salts thereof.

The invention also provides novel processes for the preparation of thefollowing compounds: ##STR3## wherein R₁, R₂, R₃, R₄, and R₁₁ are thesame as hereinabove described.

DETAILED DESCRIPTION OF THE INVENTION

The processes of the invention include a process for producing compoundsof the formula: ##STR4## wherein R₁, R₂, R₃, R₄, R₅, R₆, R₇ and R₁₁ areas hereinabove described, which comprises contacting a compound of theformula: ##STR5## with a sufficient amount of a peroxide such ashydrogen peroxide in aqueous alkali hydroxide to form a carboxamide ofthe formula: ##STR6## This compound is reacted with a hypobromite of theformula MOBr wherein M is sodium or potassium to give an amino compoundof the formula: ##STR7## recovering said amino compound and contactingsaid amino compound with a compound of the formula: ##STR8## in thepresence of dry pyridine to form a reaction product and thereafterrecovering from said reaction product a compound of formula I.

The above described process may be utilized to prepare compounds offormula II. ##STR9## wherein R₈ is halogen; R₉ is halogen or hydrogen;R₁₀ is chloro; R₁₂ is hydrogen or halogen with the proviso that R₉ mayonly be hydrogen when R₈ and R₁₂ are halogen and the pharmaceuticallyacceptable salts thereof; R₄, R₅, R₆ and R₇ are the same as hereinabovedescribed.

The invention also includes a process for the preparation of compoundsof formula I, which is based on contacting a compound of the formula:##STR10## with a para amino phenol of the formula: ##STR11## to form anintermediate compound of the formula: ##STR12## and thereaftercontacting said intermediate compound with chloroform and a compound ofthe formula: ##STR13## in the presence of anhydrous alkali to form acompound of formula I.

A further process within the scope of the present invention is concernedwith the production of compounds of the formula: ##STR14## wherein R₁,R₂, R₃, R₄, R₅, R₆, R₇ and R₁₁ are the same as hereinabove defined. Thisprocess is based on the reaction of an amino phenol of the formula:##STR15## with ethyl chloroformate in the presence of alkali, eg. NaOH,KOH, LiOH to form a compound of the formula: ##STR16## which is thenreacted with anhydrous alkali such as dry pellets of sodium or potassiumhydroxide, chloroform and a compound of the formula: ##STR17## to form acompound of the formula: ##STR18## which is thereafter contacted withaqueous alkali to form the corresponding amino compound. The aminocompound is contacted with a compound of the formula: ##STR19## to forma compound of formula III or with an aryl isocyanate to give compoundsof formula I. These processes provide exceptionally high yields of thecompounds as compared to the yields obtained by other methods.

The compounds of formulas I, II and III may be administered to mammalsincluding humans to reduce or prevent hyperlipidemia especially toreduce the levels of total serum cholesterol, low densitylipoprotein-associated cholesterol and triglycerides. The compounds maybe administered orally at a daily dosage of from about 1 to 200 mg perkilogram of body weight and more preferably at a level of about 10 to100 mg and most preferably 1 to 50 mg per kilogram of body weight. Thedaily dosage is to be administered as a single dose, or in dividedamounts three or four times a day. It is understood that the dose may bevaried according to individual sensitivity and the type ofhyperlipidemia being treated. In addition the compounds may beadministered parenterally or rectally. The parenteral dose will be15-25% of the oral dosage and the rectal dosage may be adjusted toobtain the desired therapeutic affect.

The compounds of the invention may be added to whole blood or packedcells in an amount of about 50 mg to 2.0 g per unit of blood (473 ml) orunit of packed cells (235 ml) and preferably from 250 mg to 750 mg perunit of blood or unit of packed cells in order to facilitate thedissociation of oxygen from hemoglobin and improve the oxygen deliverycapability of blood. When blood is stored, the hemoglobin in the bloodtends to increase its affinity for oxygen by losing2,3-diphosphoglycerides. The compounds of the invention are capable ofreversing and/or preventing the functional abnormality of hemoglobinwhich is observed when whole blood or packed cells are stored. Thecompounds of the invention may be added to whole blood or red blood cellfractions in a closed system using an appropriate reservoir in which thecompound is placed in dry form or in a solution form prior to storage orwhich is present in the anticoagulating solution in the blood collectingbag.

It may be desirable to administer the compound to a patient prior toand/or simultaneously with the transfusion of the treated whole blood orred cells in order to avoid substantial variations in the hemoglobinoxygen affinity due to dilution that occurs when the blood isadministered.

The compounds may be administered to patients in whom the affinity ofhemoglobin for oxygen is abnormally high. Particular conditions includecertain hemoglobinopathies and certain respiratory distress syndromes innewborn infants aggravated by high fetal hemoglobin levels and when theavailability of hemoglobin to tissues is decreased (e.g. in ischemicconditions such as peripheral vascular disease, coronary occlusion orcerebral vascular accidents). The compounds may also be used to inhibitplatelet aggregation and may be used for antithrombotic purposes. Thedosage for the modification of the affinity of hemoglobin for oxygen maybe based on the dosages set forth above for hyperlipidemia and thesedosages may be adjusted for parenteral use to obtain the desiredtherapeutic result. The compounds should not be administered to patientswith sickle cell disease to avoid the possibility of excessive oxygenloss which may precipitate a sickle cell crisis.

The compounds may also be administered at levels of 1 to 100 mg in asingle dose per kilogram of body weight alone or combination with oxygenin conjunction with radiation therapy or with chemotherapy for malignantconditions such as solid tumors of the breast, stomach, colon and theirmetastatic lesions. The compounds should be administered sufficientlyprior to the initiation of chemotherapy or radiation therapy so that theblood level of the compound will be at a maximum. This will increase theefficacy of the treatment and/or make it possible to reduce theradiation or drug dose and reduce the associated toxicites. Thecompounds may also be used at levels of 1-100 mg per Kg of body weightfor treatment of CO poisoning to facilitate dissociation ofhemoglobin-bound CO and its replacement with oxygen. Efficacy of thistreatment will be increased if the compounds are administeredsimultaneously with oxygen.

As used herein the term halogen is used to include bromo, chloro, fluoroand iodo; the term alkyl includes straight and branched chainhydrocarbon groups of 1-6 carbon atoms such as methyl, ethyl, n-propyl,n-pentyl and the like; the term aryl includes phenyl and naphthyl; theterm cycloalkyl includes cycloaliphatic groups of 3 to 7 carbon atomssuch a cyclopropyl, cyclobutyl, cyclohexyl and the like; the term alkoxyis used to include R₁₃ OH groups wherein R₁₃ is alkyl of 1 to 6 carbonatoms; the term aralkyl is used to include phenalkyl groups wherein thealkyl portion is an alkylene moiety of 1-6 carbons such as benzyl,phenethyl, phenpropyl and the like. The meaning of R₁, R₂, R₃, R₄, R₅,R₆, R₇, R₈, R₉, R₁₀, R₁₁, R₁₂ and R₁₃ are the same for each formulaexcept where specific meanings are set forth.

The term pharmaceutically acceptable diluent is used to include liquidand solid materials utilized to prepare injectable dosage forms andsolid dosage forms such as tablets and capsules. Water may be used forthe preparation of injectable compositions which may include buffers andagents to render the injectable composition isotonic. The solid diluentsand excipients include lactose, starch, conventional disintegratingagents, coatings and the like. For example, UK patent no. 1,535,683,which is incorporated by reference, gives several embodiments offormulation that may be utilized in the preparation of tablets andcapsules.

EXAMPLE 1 2-(4-cyanophenoxy)-2-methylpropionic acid

To a warm stirring mixture of 4-cyanophenol, 5.95 g (0.05 mole) and 11 gNaOH in 45 ml acetone, chloroform. 3.8 ml was dropwise added during 20minutes. The reaction mixture was then refluxed for 4 hours. Excess ofacetone was evaporated. The residue was dissolved in 100 ml cold water,charcoaled and filtered. Acidification gave 10 g (near theory) of whitecrystalline powder, MP 118°-120°.

2-(4-carboxamidophenoxy)-2-methylpropionic acid

2-(4-cyanophenoxy)-2-methylpropionic acid 11.3 g (0.055 mole) was addedto a solution of 280 ml 3% hydrogen peroxide and 8 g KOH in 32 ml H₂ Oin a 1 lit. flask. The mixture was stirred until gas evaluation andexothermic reaction was terminated. After cooling, the reaction mixturewas acidified (HCl) to give 10.8 g (88%) of a white crystallinecompound, MP 202°-204°.

2-(4-Aminophenoxy)-2-methylpropionic acid

2-(4-carboxaminophenoxy)-2-methylpropionic acid, 11.15 g (0.05 mole)were gradually added to a cold stirring solution of 3 ml bromine whichwere added to an ice cold solution of 12 g NaOH in 100 ml water.Stirring continued for 5 minutes to dissolve the amide. The solution wasthen warmed to about 75° for 20 minutes. The colored solution was cooledand acidified with acetic acid giving 8.84 (90%) of colorless small3,5-dichlorophenyl isocyanate to form2(4(3,5-dichloro-phenylureido)phenoxy) 2-methylpropionic acid.

EXAMPLE 2 4-ethoxycarbonylaminophenol

This already reported compound (Beilstein Der Organischen Chemie 13 478(1930), was prepared by the following method:

p-aminophenol 33.36 g (0.3 mole) and 12 g NaOH were dissolved in 120 mlwater and cooled to ice salt bath temperature. To the stirring solution,24 ml ethylchloroformate were slowly added. A white precipitate wasfound. One gram sodium dithionite was added and mixed. The solid wasfiltered by suction and washed with cold water (50 ml).Recrystallization from hot water gave a crystalline powder, 48.3 g(89%), MP 120°-123°.

2-(4-aminophenoxy)2-methylpropionic acid

4-ethoxycarbonylaminophenol 6.335 g (0.035 mole) and 7.5 g NaOH wereadded to 30 ml acetone. To the refluxing mixture 2.5 ml chloroform weredropwise added. While the mixture was stirring, it was refluxed for fourhours. Excess of the solvent was evaporated. The residue was dissolvedin water and acidified. A light brown oil was obtained which slowlyturned to a crystalline mass 4.5 g (48%) mP 82°-83°. The above ester wasboiled with 45 ml 10% KOH in water for half hour. After cooling, thereaction mixture was acidified with concentrated acetic acid to give2.86 g (87%) of desired compound. This compound may be reacted with theisocyanate as in Example 1 to form the same product of Example 1.

EXAMPLE 3 2-(4-aminophenoxy)-2-methylpropionic acid

To a refluxing mixture of 4-ethoxycarbonylaminophenol 12.67 g (0.07mole) and 15 g NaOH in 60 ml acetone, 5 ml chloroform were dropwiseadded. Stirring and refluxing continued for 4 hours. At the end, excessof acetone was evaporated. A solution of 20 g KOH in 75 ml water wasadded and boiled for half hour. After cooling, the solution wasacidified with acetic acid to give 2-(4-aminophenoxy)-2-methylpropionicacid as a white crystalline compound, 7.15 g (51%), MP 216°-218°.

2-(4-(3,5-dichlorobenzamido) phenoxy)2-methylpropionic acid

To a solution of 0.5 g 2-(4-aminophenoxy)-2-methylpropionic acid in 5 ml2N NaOH, 0.70 ml 3,5-dichlorobenzoyl chloride was dropwise added withstirring 5 ml additional 2N NaOH was gradually added to keep the PHstrongly alkaline during the reaction. After 1 hour stirring, thereaction product was acidified with HCl. The white precipitate wasrecrystallized from aqueous isopropanol to give 1.4 g (76%) of finecrystals MP 206°-207°.

EXAMPLE 4 2-(4-(3,5-Dichlorophenylureido)phenoxy)-2-methylpropionic acid

To a stirring solution of 4.95 g (0.025 mole) of2-(4-aminophenoxy)-2-methylpropionic acid in 50 ml dry pyridine, 4.95 g(0.025 mole) of 3,5-dichlorophenyl isocyanate were added. After 1 hourstirring at room temperature, 150 ml water was added and the mixture wasacidified with concentrated HCl. The precipitate was filtered, washedseveral times with cold water and dried. Recrystallization from aqueousacetone gave small plates 1.81 g (94%) MP 182°-184°.

EXAMPLE 5 2-(4-(2,4,5-trichlorophenylureido)phenoxy)-2-methylpropionicacid

This compound was prepared in pyridine as described in Example 4. Yield96% MP 216°-216°.

EXAMPLE 6 2-(4-(3,4,5-trichlorophenylureido)phenoxy)-2-methyl propionicacid

This compound was prepared in pyridine as described in Example 4. Yield90% MP 233°-235°.

The structure of all compounds prepared were confirmed byspectroscopical and analytical methods.

EXAMPLE 7

2-(4-(3,4-dichlorophenylureido)phenoxy)-2-methylpropionic acid

To a stirring solution of 1.09 g (0.01 mole) P-aminophenol in 10 mlpyridine, 1.88 g (0.01 mole) 3,4-dichlorophenylisocyanate were added.The reaction was exothermic. After 20 minutes, stirring at roomtemperature, 50 ml water were added and pyridine was neutralized bydropwise addition of 5% HCl. The white crystalline powder was filtered,washed with water and dried giving 2.95 g (99%) of desired compound, MP208°-210°. A mixture of the 1-(3,4-dichlorophenyl)-3-(4-hydroxyphenyl)urea 2.5 g, NaOH 1.79 g in 12.05 ml acetone was stirred and heated toreflux. To the mixture, 0.85 ml chloroform was dropwise added. After 4hours refluxing, most of acetone was evaporated. The residue wasdissolved in 50 ml hot water, charcoaled and filtered. It was thenacidified with HCl. The compound was recrystallized in 20% acetic acidor aqueous acetone to give 2.6 g (81.5%), MP 183°-184°.

EXAMPLE 8 2-(4-(3,5-difluorophenylureido)phenoxy)-2-methylpropionic acid

This compound was prepared in pyridine according to the general methodof Example 4. Yield 92%. MP 181°-183°.

The compounds synthesized according to the procedures described in thispatent application were tested for their abilities to modify theaffinity of hemoglobin for oxygen. The test procedures employed includeddetermination of the standard oxygen dissociation curve by HemoxAnalyzer (ICS Med. Products, Huntington Valley, Pa.). In this test, P50represents the partial pressure of O₂ (in mmHg) at which 50% of theoxygenated hemoglobin is converted to hemoglobin. Compounds which reduceaffinity of hemoglobin for oxygen shift the dissociation curve to theright and increase the P50 values. The results of these tests are givenin Table 1 comprising activities of various compounds at variousconcentrations tested against a solution of purified hemoglobin or astandard suspension of human red blood cells in HEPES buffer at pH 7.4.

                  TABLE 1                                                         ______________________________________                                        Concentration   P50%                                                          Compound                                                                              (mM)        Hemoglobin Red Blood Cells                                ______________________________________                                        1       0           8.25±2  12±1.68                                     2       1.0         --         16±1.32                                             0.2         8.5        --                                             3       1.0         --         64                                                     0.2         --         25.5                                           4       1.0         --         35.5                                                   0.5         --         33                                                     0.2         10         22.5                                           5       0.2         12         15                                             6       0.5         45         57.5                                                   0.2         20.5       26                                             7       1.0         --         18                                                     --          --         14                                             8       0.2         61         --                                                     0.1         21         --                                             9       0.2         64         --                                                     0.1         25         --                                             ______________________________________                                         1. Control HEPES buffer at pH 7.4                                             2. Bezafibrate                                                                3. 2(4-(3,4-dichlorophenylureido)phenoxy)-2-methylpropionic ac                4. 2(4-(2,4-dichlorophenylureido)phenoxy)-2-methylpropionic ac                5. 2(4-(2,5-dichlorophenylureido)phenoxy)-2-methylpropionic ac                6. 2(4-(3,5-dichlorophenylureido)phenoxy)-2-methylpropionic ac                7. 2(4-(3,5-difluorophenylureido)phenoxy)-2-methylpropionic ac                8. 2(4-(2,4,5,-trichlorophenylureido)phenoxy)-2-methylpropion                 9. 2(4-(3,4,5-trichlorophenylureido)phenoxy)-2-methylpropioni                 A dash indicates that no test was carried out.                           

The exceptionally high activities of compounds 6, 8 and 9 are documentedin Table 1 not only by their higher P50 values as compared tobezafibrate and compound 3, but also by the observation that for allcompounds except for compounds 6, 8 and 9, the activity rapidly fallsoff or is lost when the concentration is reduced to 0.1 mM.

Compounds 8 and 9 show exceptional in vitro activity even at 0.1 mMconcentration..

The commercial compound bezafibrate has no activity in this test atlevels below 0.5 mM.

We claim:
 1. A method for treating hemoglobin or blood in vivo or invitro to modify the affinity of hemoglobin for oxygen, said methodcomprising causing an effective amount of a compound of the formula:##STR20## wherein R₄ is selected form the group consisting of hydrogen,halogen, straight and branched chain alkyl of from 1 to 6 carbon atoms,aryl, cycloalkyl of 3 to 7 carbon atoms; and alkoxy of 1 to 6 carbonatoms; R₅ and R₆ may be the same or different and are selected from thegroup consisting of hydrogen, halogen, straight or branched chain alkylgroups of 1 to 6 carbon atoms; aralkyl groups wherein the alkyl portionhas from 1 to 6 carbon atoms, cycloalkyl of from 3 to 7 carbon atoms andaryl; R₇ is hydrogen or a straight or branched chain alkyl group of 1 to6 carbons; R₈ is halogen; R₉ is hydrogen or halogen with the provisothat R₉ may only be hydrogen when R₁₂ is halogen; R₁₀ is hydrogen orhalogen and R₁₂ is hydrogen or halogen, and the pharmaceuticallyacceptable salts thereof to come in contact with hemoglobin.
 2. A methodas defined in claim 1 wherein R₄ is hydrogen, R₅ and R₆ are methyl, R₇is hydrogen, R₈ is chloro, R₁₀ is chloro and R₁₂ is hydrogen.
 3. Amethod as defined in claim 1 wherein the hemoglobin is treated in vivo.4. A method as defined in claim 1 wherein the hemoglobin is treated invitro.
 5. A method as defined in claim 2 wherein the hemoglobin istreated in vivo.
 6. A method as defined in claim 2 wherein thehemoglobin is treated in vitro.